Bone screws are used for a variety of surgical purposes, including the immobilization of fractured bone segments to aid in the healing process, and as an adjunct to spine fusion surgery to help hold implants in place. With respect to the later, a need exists for bone screws that furnish improved pull-out strength under axial, distractive, and compressive force loads applied through the patient's natural movement. There is also a need for bone screws with easier implantation and reduced insertion time.